/Engine/Plugins/Experimental/Mutable/Source/CustomizableObject/Classes/MuCO/CustomizableObjectSystem.h
[Texture Parameters] Add a new image provider to the CustomizableObject System. This will be queried for when an external image ID is provided to mutable in an Texture Parameter node.
void RegisterImageProvider ( [UCustomizableSystemImageProvider](API\Plugins\CustomizableObject\MuCO\UCustomizableSystemImageProvider) * Provider )